Arizona duo work on high-tech bomb detector

TUCSON, Ariz. (AP) — University of Arizona researchers are developing a bomb-detecting device 1 million times more sensitive than those used by the military today.

M. Bonner Denton and Roger Sperline, of the UA Department of Chemistry and Biochemistry, received a $5 million grant from the U.S. Department of Defense to build the "bomb sniffer," which they call a Real Time Atmospheric Mass Spectrometer.

"Currently, the only 'instrument' we have that can detect explosives from a distance is a dog," said Denton, a professor of chemistry. "A dog can smell a bag of TNT from 2 or 3 feet away."

Military and airport security workers use hand-held devices to detect bombs, Denton said, but these require operators to swab suspicious packages or baggage. The major drawback is the need to get extremely close to dangerous explosives, he said.

The new device takes the science behind bomb detection a huge leap forward. It allows soldiers and security personnel to find bombs from 140 feet away.

The device is informally referred to as a "bomb sniffer," but smelling is not quite how it works. It uses a technology called mass spectrometry to split an unknown substance into its most basic components - charged atomic particles called ions. Researchers then analyze these tiny fragments to determine a sample's composition.

"Our instrument is the most sensitive technology in the world today for detecting trace-level explosive compounds in a diluted body of air," Denton said.

Sperline, a chemistry researcher who has been collaborating with Denton for more than a decade, said the device puts an electric current into a body of air, ionizing it and creating a magnetic field.

The electricity in the air transfers a charge to compounds of the explosive material, accelerating them. An operator can then manipulate the magnetic field to move ions to a detection plate.

Sperline said the machine identifies a compound's unique mass by determining the time it takes for it to move from one point of the magnetic field to a detector.

The compounds in TNT and plastic explosives are unique, he said, "so there is very little interference in our detection or determination of explosives."

The project for the Defense Department builds on a recent breakthrough Denton made to dramatically improve the detection capabilities of mass spectrometers.

Previous technology monitored for one atomic mass at a time. Denton developed a "focal detector array" that scans for thousands of atomic masses at once, allowing him to identify compounds in a few minutes.

His work garnered him a Research and Development 100 award, given to the top 100 scientific inventions of the past year by R&D Magazine.

Sperline and Denton are working to reduce the cost and size of their machine - currently the size of a small computer - and toughening it to military specifications.

"The device works fine, but, of course, to mil-spec any type of instrumentation requires a huge amount of testing and engineering," Denton said. "We have to develop it in such a way that it can be dropped out of the hull of an airplane onto a tarmac and still work."

Denton said the device has a host of potential uses.

"We are interested in pursuing the use or modification of this technology for screening humans for a wide spectrum of diseases," he said.

People with diseases such as diabetes and certain types of cancer exhale identifiable particles when they breathe, Denton said.

The mass spectrometer can identify those compounds, he said.

"An example would be a particular compound one exhales if they have prostate cancer," Denton said. "It would be an extremely cheap and easy way to screen large segments of the population for diseases."

Denton said the spectrometer probably won't be seen in the medical field anytime soon, but it could redefine how we look for explosives, weapons, diseases and more.